Benjamin pitchee



B. PITCHER. Machine for Bending MetallicMold Boards.

Patented April 27, 1858.

UNITED STATES PATENT OFFICE.

BENJN. PITCHER, OF PEORIA, ILLINOIS, ASSIGNOR TO HIMSELF, WM. TOBEY, ANDJOHN ANDERSON, OF SAME PLACE.

BENDING MOLD-BOARDS FOR FLOWS.

Specification of Letters Patent No. 20,128, dated April 27', 1858.

To all whom "it may concern;

Be it known that I, BENJAMIN PITCHER, of Peoria, Peoria county, in theState of Illinois, have invented certain new and useful Improvements inMachines for Bending Metallic Mold-Boards for Plows, of which thefollowing is a full, clear, and exact description, reference being madeto the accompanying drawings, forming part of this specification.

Figure 1, represents a perspective view of a machine for bending moldboards for plows, embracing my improvements. Fig. 2 represents an endelevation of the upper and lower die, with the plate in position to bebent.

In manufacturing mold boards for plows from wrought iron or steelplates, great difiiculty is experienced in giving to the plates a set,or permanent bend, so that they will retain the shape imparted to themby the forming dies or rollers. This difliculty arises from theelasticity of the material, as well as the light curve of the moldboard.

In bending metal plates, it is necessary in order that the plate mayretain the form given to it when released from the machine, that itshould be so acted upon during the process of bending, as to cause arearrangement of the molecules or fibers of the metal, so as to conformto the curves and bends given to the plate by the bending dies orrollers.

The machines heretofore constructed for bending mold boards for plows,bend without compressing or drawing the plate, so as to produce arearrangement of the fibers of the metal; hence it is that, the platesbent by these machines do not permanently retain their form, but springout of shape.

To overcome this defect, and thus give a permanent set to the plateduring the process of bending, is the object of my improvement, and myinvention for effecting this object, consists in the arrangement of thebending dies, and in the position in which they are hinged, or connectedwith each other, so that they will bend the plate nearly into shapewithout cramping it and then compress and draw it from the rear to thefront of the dies, without releasing the The lower and convex die (B) isfirmly s ecured to the table, and to it is hinged the concave die (C),by ears (a, 6) cast on the straight edge of both dies, through holes inwhich passes a rod (61) and connects the dies. A link (E) hingedto thefront edge of the upper die is also pivoted at its lower end to a lever(D) by which power is applied to operate the upper die.

The plate to be bent is heated to a red heat, and entered between thedies; the rear end of this plate resting against the lower edge of theupper die, and on the convex surface of the lower. As the upper die isbrought down, its front end comes against the outer edge of the plate,and bends it around the lower die nearly into shape before it is graspedor held in any manner that would prevent the whole upper and convexsurface of the plate from stretching or being drawn out while it isbeing bent to the curve of the lower convex die. The dies first close onthe plate at the rear end, holding it at this point, and as they areclosed, the plate is gradually compressed and drawn out or stretchedfrom the rear to the front of the dies, and parallel to their center ofmotion, and no portion is released after being compressed, until theentire plate is bent, compressed and drawn, which causes a rearrangementin the fibers of the metallic plate to conform to the curve given to itby the dies, so that a permanent set is given to bends in the plate.

Having thus described my improvement in machines for bending mold boardsfor plows, what I claim thereon as new, and desire to secure by LettersPatent is.

The combination of the stationary die until the entire bending iscompleted for (B) with the movable die (0) hinged to the the purposedescribed. 10 stationary, and constructed and arranged as In testimonywhereof I have subscribed described, so that the heated metallic platemy name. subjected to their action is during the BENJAMIN PITOHER.process of being bent into shape gradually Witnesses: compressed anddrawn from its inner to its WM. WVEIs, outer edge and retained undercompression WILLIAM TOBEY.

